Navy taskforce will be forced to rely on France and America

Drastic cutbacks in spending on the Royal Navy during the past decade means commanders are struggling to assemble a task force to participate in the UN-sanctioned blockade of North Korea.

Navy chiefs have also expressed deep concern about their ability to defend their ships against a hostile missile or fighter threat after a decision was enforced six months ago to scrap the Sea Harrier fighter. Ships will be entirely reliant on the American or French navies to provide "beyond visual range" air defence with aircraft carriers.

The Navy has been cut by almost a third since Labour came to power and commanders believe that any British contribution would amount to one or two ships. While the Navy has operational experience of interdicting drugs and arms smugglers in the Gulf and Caribbean, its resources are severely limited.

Since 1997, the number of frigates and destroyers has shrunk from 35 to 25 warships, one of three aircraft carriers has been taken out of service and the hunter killer submarine force has been cut by two boats to 10. There are 38,000 sailors in the Navy.

The Government was publicly warned that 25 frigates and destroyers were inadequate for the demands being made on the Fleet by the recently retired First Sea Lord Admiral Sir Alan West.

"We need far more hulls for what they want us to do," a senior Navy officer told The Daily Telegraph. "We cannot be in all these places at once. I am staggered that the Government is trying to make this commitment when it knows what our Armed Forces are going through."

Ministry of Defence sources said that because the UN resolution required an international effort "any contribution by us would be looked at" and deploying a warship was "always a possibility".

The Foreign Office said it would be liaising with its security council partners this week "to discuss the practical implementation of the resolution".

A frigate would be able to carry out stop and search missions with its helicopters and armed boarding parties. A Trafalgar or Swiftsure class submarine could also be used to covertly gather intelligence off the North Korean coast.

But without the Sea Harriers the ships will be vulnerable to attack if there are no US Navy Aegis class ships in the area. "Without Sea Harrier we are screwed and we cannot really protect ourselves adequately from the missile threat," the Navy officer said.

The Fleet will not have adequate air defence until the first Type 45 destroyer enters service in three years.

Richard Scott, the Navy editor of Jane's Defence Weekly, said recent cuts had placed "far greater limitations" on the number of tasks the Navy could undertake.